Drive for calculating-machines



E. S. ENSIGN.

DRIVE FOR CALCULATING MACHINES.

APPLICATION FILED MAR. I0, 1916.

Patented Feb. 24,1920.

lnvenror. Emory S. Ensign by wzwrf ATTys.

always. nnsrcn, or new YORK, N. Y.

DRIVE FOR CALCULATING-LIACHINES.

' Specification of Letters Patent. Patented Feb. 24, 1920.

Application filed March 18, 1916. "Serial No. 83,401.

To all whom it may concern:

- Be it known that I, EMORY S. ENSIGN, a citizen of the United States, residing at New York city, New York, have invented an Improvement in Drives for Calculating-Machines, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to an'improvement in calculating machines and more particularly to driving mechanism adapted to be used in such machines.

It is common at present to employ a spring motor to rotate the meter or indiciabearing means upon which the numerical results are displayed to the operative as the necessary torque is not readily built up by the small electric motors available for thispurpose and, furthermore, the strain of the constant starting under the maximum load is highly detrimental to this type of power source. Such spring motor is automatically re-wound, when its tension drops below a predetermined point, by the intermediary of an electric motor.

' In this improvement an electric motor or other power means is employed, and, during the operation of the calculating machine, the power source runs continuously. The transmission of the power is effected through the interposition of a novel driving mechanism and clutch. It was found undesirable to employ a clutch which throws; the power into and out of engagement sharply, as the resultant rebound or jump of the meter or numeral-bearing wheelsentails liability to inaccuracies in the arithmetical results. Therefore, there has been produced a drive and transmission-which very suddenly accelerates to a direct drive and which, when thrown out of engagement with the power source, eflectuallyprevents backlash or rebound in the driven members.

An object of this invention is to provide an efficient driving mechanism for calculat -1ng machlnes.

- Another object is to provide a drive and clutch mechanism which will obviate the jump and' rebound of the index wheels or meter. 4

A further object is to reduce the size and construction costand lighten theweight, and to produce a machine quiet in operation.

Other objects of the invention will more fully appear from the following description and the accompanying drawings and will be pointed out in the annexed claims.

In the drawings,

Figure 1 is a side elevation of the novel clutch and drive as applied to a calculating machine;

Fig. 2 is a section on the line 2-2 of Fig. l;

Fig. 3 is a section on the line 33 of Fig. 2.

In this selected embodiment of the invention disclosed in the accompanying drawings, the machine is inclosed in a suitable casing 1, aluminum being the material preferably employed in order to keep the weight of the machine as low as compatible with efficiency. and durability. The shaft 2, which carries the numeral index wheel composing the 'meter upon which the arithmetical result is suitably displayed to the operative, is journaled in the casing 1. One of the journals is shown in section in Fig. 2. They consist each of a standard 3 having an offset portion affording a bearing 1 for the shaft 2. The casing 1 has, preferably, similar end slots 5, one being shown in Fig. 2. The slots receive the shaft end portions in the assembling of the incased machine. The clutch means is disposed between the drive and the meter in this selected embodiment. It has heretofore been customary to have a clutch or stop-motion at the end of the shaft opposite the drive. Defects in this construction developed in that the whole meterbearing shaft between'the clutch and drive was subject to torsional displacements due to the shaft flexibility and to the inertia or to the momentum of the parts attendant upon sudden starting and stopping. The

result was that the meter or index wheels often jumped past the-correct indications rendering the machine inaccurate. Herein, the maximum play of shaft torsional strain is confined substantially to one end of the shaft, viz., that included between the drive and the clutch which members in this selected embodiment are positioned relatively close together at one end of the shaft.

The driving mechanism here disclosed may be employed in various modes but, is in this embodiment incorporated in a calculating machine. Herein, an indicator-bearing shaft is under constant torque transmitted thereto through the intermediary of a pair of members, one of which is constantly driven from a suitable power source and is in constant frictional engagement with the other, the latter being secured to and revoluble with the shaft. A clutch member is fixedly secured to the shaft and, while so constructed to have its revolution normally prevented, it is releasable at will;

' This embodiment of this novel drive and this end, the body 8 of the pulley bears a I peripheral flange 9 which is preferably annularly recessed to receive a belt 11. The :belt 11 is actuable' by any suitable power source and, as shown, is driven by the electric'motor 12 mounted upon a pivoted bracket 10 secured to the machine casing 1.

The turnbuckle 13, movable in bosses on the motor and machine casings, respectively, functions as a means 'fortightening the belt .11 through the movement of the motor in an are about its pivotal mounting. A disk l t is secured to the shaft 2 by means of the pin 15 and'is revoluble with the shaft. The pulley upon its inner face carries means for engaging frictionally the disk 14 by which means a turning moment is constantly imused. for self-lubricating bearings. plates 16 are preferably tensionally held parted to the shaft 2. a

In this embodiment of the invention, the

disk 14 is composed of ametallic substance,

preferably steel, and its face, presented to the pulley friction means, is highly polished. The frictionally engaging means of the pulley comprise a plurality of small washers, disks or plates 16, three being shown in this embodiment. These plates are preferably circular in form and are secured,

substantially equi-distantly, upon the inner pulley face by means of any suitable fastenings such as rivets17. Each plate is held against any, tendency to rotatory movement about its rivet by means of a pin 18. These plates may be formed of any suitable substance but it has been found that what is known in the trade as 'arguta wood functions eliiciently for this purpose. This wood is a rock maple or similar wood treated with a wax or oily substance and is commeplly against the polished face of the disk 14: by

- fmea'ns' of a spring functioning to push inwardly the'pulley upon the shaft. Such s rin 19 may beof the coiled type, and is retained within a cap 20 fitted over the end of "the shaft and held against dislodgment by means of the pin 21. The pulley end of thespring bearsagainst a preferably hardened and polished washer 22 interposed beshaft.

be increased or diminished as desired by the interpositionof one or more similar washers 23 in the cap between the spring end and the head of the cap inside,,or:byincreasing the number or thickness of the washer 22.

The eflicient tension of the spring having 7 been once fixed,the wear of the parts being very slight, it is deemed preferable to make this construction fo0l-proofby having the pin 21 countersunkin the cap 20. To the average operative, apparently the spring cap cannot be removed and the tension altered except by demounting a large portion of the machine; but, the cap is readily removed by inwardly pushing the cap against the tension of the spring when the pin 21 is readily removed from the shaft aperture.

. A- constant torque is thus normally imparted to the shaft 2. A stop or clutch member is interposed upon the shaft 2 between the drive andthe meter comprising the usual index wheels which are not necessary to be shown. The function of this clutch member is normally to hold the shaft 2 against revolving. It is so constructed thatrevolution of the shaft may readily be 7 permitted as desired. A disk 24 is mounted upon the shaft 2 and is held revoluble with the shaft by the pin 25. 7 An arm 26 is secured by thescrew 27 to the face of this disk which is toward the drive endof the shaft. Thisarm .hasxa terminally oflset portion 'or shoulder .28 whichis normally engaged by a stop which prevents movement of the disk. This stop member is movable to release the disk arm by means of a system of levers actuated by the usual adding bar of the calculating machine, A setof, levers to control the release of the clutch disk is shown in the'drawingsthough obviously they may be of any type effecting the desired disk-controlling function. In

.theembodiment here illustrated, the arm 29 is pivotally mounted on the casing. The lower end of this arm is preferably forked,

having two lateral armsterminally offset and forming the shoulders 30., In normal position the shoulder adjacent the disk pro ects within the'path of traverse of the arm 26 and revents movement ofthe disk and he endportion 31 of a bell crank lever, similarly pivotally mounted is received between the two shoulders 30. A spring 82 secured to the opposite arm 33 of the bell crank 'lever and to the casing 1, normally tends upwardly to push this arm 33 and hence inwardly to hold the shoulder 30in the path of the shoulder 28 of the disk arm 26. The usual adding bar'34 on the front of the calculating machine is mounted so that upon its manual depression, its boss 35 will depress the arm 36 of a pivoted bell-crank lever. The arm 37 of such lever, contacting with the arm 33 will depress the latter against the tension of the spring 32. Thus, upon the depression of the bar 3 the pivoted arm 29 is withdrawn.

In operation the device is simple, efficient, durable and overcomes effectively the disadvantages of the present drive. When'it is desired to permit the revolution of the shaft 2 in order to cause the meter or index wheels to function, the adding bar 34 is downwardly pressed. This force trans mitted through the lever system effects the withdrawal of the shoulder 30 from engagement with the shoulder 28 of the disk arm 26. The disk 24: and shaft 2 are then freely revoluble under the torque constantly imparted to the shaft by the novel driving mechanism herein. The pick-up or acceleration is certain and rapid and without jar, jump or noise, nor is an electric motor over-taxed by a sudden load, as the load on the power source is substantially constant. When the key-bar is depressed, it is immediately released so that the shoulder 30, under the indirect action of the spring 32, immediately resumes its place in the path of the shoulder 28 of the disk arm. The revolution of the shaft having been comleted, the further movement is arrested y the engagement of the disk arm and the stop or arm 29. The stoppage of the shaft is certain and without rebound or back-lash as the turning force is still applied to the shaft and holds the shaft immovable with the disk arm against the stop.

There is thus provided an eflicient, simplified clutch and drive adaptable to various uses and which when used in a calculating machine will prevent jump of the meter at at finish of its worktion disclosed herein is illustrative but not restrictive and that the same may be modified within the meaning and scope of the claims which follow.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A driving mechanism comprising a driving element, a driven member having a smooth bearing face, a plurality of frictional, self-lubricating plates radially and equidistantly secured to said driving element, means tensionably to press the plates toward the driven member whereby the plates frictionally engage said bearing face and impart a constant torque to the driven member, and means normally preventing rotation of the driven member and operable to permit rotation thereof.

2. A driving mechanism comprising a driven disk, a driving element, said disk and driving element having adjacent opposed faces, a plurality of friction devices se-- cured to the face of the driving element and revoluble therewith and severally engaging the face of the disk whereby a constant torque is imparted to the disk, and means normally preventing rotation of the disk and operable to permit rotation thereof.

3. A driving mechanism comprising a driven element, a driving element, one of said elements presenting a plane surface perpendicular to the axis of rotation and opposed to the other element, self-lubricating frictional means secured to the said other element and revoluble therewith and frictionally engaging said plane face whereby a constant torque is imparted to the driven element, and means normally preventing rotation of the driven element and operable to permit rotation thereof.

a. A driving mechanism comprising the construction defined in claim 3 in which the said self-lubricating frictional means is composed of a plurality of radially disposed plates of arguta wood.

5. A driving mechanism comprising the construction defined in claim 3 in which the said self-lubricating frictional means is composed of a plurality of radially disposed plates of wood treated with a suitable wax or oily substance.

In testimony whereof, I have signed my name to this specification.

EMORY S. ENSIGN. 

